diff --git a/public/openapi/components/schemas/PostObject.yaml b/public/openapi/components/schemas/PostObject.yaml
index 526bc2c75e..5ff918cd7f 100644
--- a/public/openapi/components/schemas/PostObject.yaml
+++ b/public/openapi/components/schemas/PostObject.yaml
@@ -74,9 +74,6 @@ PostObject:
           description: A category identifier
         slug:
           type: string
-        thumb:
-          type: string
-          description: An uploaded topic thumbnail
         deleted:
           type: number
         postcount:
diff --git a/public/openapi/components/schemas/TopicObject.yaml b/public/openapi/components/schemas/TopicObject.yaml
index 6f2c45cfcf..10453fe22b 100644
--- a/public/openapi/components/schemas/TopicObject.yaml
+++ b/public/openapi/components/schemas/TopicObject.yaml
@@ -41,9 +41,6 @@ TopicObject:
       type: number
     locked:
       type: number
-    thumb:
-      type: string
-      description: An uploaded topic thumbnail
     pinned:
       type: number
       description: Whether or not this particular topic is pinned to the top of the
@@ -224,6 +221,8 @@ TopicObject:
         description: HTML injected into the theme
     index:
       type: number
+    thumb:
+      type: string
   required:
     - tid
     - uid
diff --git a/public/openapi/read/topic/tid/id.yaml b/public/openapi/read/topic/tid/id.yaml
index fab2532476..cdc638a1f5 100644
--- a/public/openapi/read/topic/tid/id.yaml
+++ b/public/openapi/read/topic/tid/id.yaml
@@ -42,9 +42,6 @@ get:
                 type: number
               viewcount:
                 type: number
-              thumb:
-                type: string
-                description: An uploaded topic thumbnail
               deleted:
                 type: number
               locked:
diff --git a/public/openapi/read/topic/topic_id.yaml b/public/openapi/read/topic/topic_id.yaml
index d293d37ce5..c55c6888cd 100644
--- a/public/openapi/read/topic/topic_id.yaml
+++ b/public/openapi/read/topic/topic_id.yaml
@@ -53,9 +53,6 @@ get:
                     type: number
                   viewcount:
                     type: number
-                  thumb:
-                    type: string
-                    description: An uploaded topic thumbnail
                   postercount:
                     type: number
                     description: The number of unique users who made a post in this topic
diff --git a/public/openapi/read/unread.yaml b/public/openapi/read/unread.yaml
index 9af7956705..a5fe83348e 100644
--- a/public/openapi/read/unread.yaml
+++ b/public/openapi/read/unread.yaml
@@ -49,9 +49,6 @@ get:
                           type: number
                         viewcount:
                           type: number
-                        thumb:
-                          type: string
-                          description: An uploaded topic thumbnail
                         postercount:
                           type: number
                         teaserPid:
diff --git a/src/topics/data.js b/src/topics/data.js
index d33ddb29d0..720d2e63ad 100644
--- a/src/topics/data.js
+++ b/src/topics/data.js
@@ -98,7 +98,9 @@ function modifyTopic(topic, fields) {
 
 	escapeTitle(topic);
 
-	topic.thumb = validator.escape(String(topic.thumb)) || '';
+	if (topic.hasOwnProperty('thumb')) {
+		topic.thumb = validator.escape(String(topic.thumb));
+	}
 
 	if (topic.hasOwnProperty('timestamp')) {
 		topic.timestampISO = utils.toISOString(topic.timestamp);